This is the tale of a boy who became the only Adam among four billion Eves. In a world where a pandemic has left all men impotent, high school student Itsuki is the sole exception. To keep this secret safe, he transfers to a very special high school, which happens to be 90% female. There, he meets an upbeat and friendly senior, a sexually frustrated female teacher, a tomboyish school "prince," and an heiress from a wealthy family. For Itsuki, who can choose any woman in the world, the question remains: which one will he pick?